I have a Image 15.0 R treadmill. It skips and I tried tightening the belt 1/4 turn as directed and not over tighten it. Still skips and actually squeaks now especially when running on the treadmill at 6 mph or greater. Even walking at 4 mph it is skipping - problem seems to be getting worse - can no longer run or walk on it
3 different possibilities in my opinion:
belt is too loose, belt is too tight, belt is worn out.
Try to lift the belt and get your hand under it in the middle of the deck. If you cannot reach, it is possible that your belt is too tight. Another clue for this would be the belt "curling" on both sides at the edges. Try to loosen the belt, gradually and testing it along the way.
If on the contrary you can easily slide your hand under the belt from one side to the other, it is more likely that the belt is too loose. The squeaking might be due to the belt not being "square" on the deck. Try to loosen it even more until you can slide it with your hands across the deck. And have it aligned evenly at the front and back. Then retighten and adjust the tracking at low speed.
!!! Do not over loosen as the bolts might come out of the back roller.
A worn out belt might squeak and skip when its old. Read More At : Image 15.0R Treadmill Walking Belt...